Diagonal magnetoelectric susceptibility and effect of Fe doping in the polar ferrimagnet Mn2Mo3O8

作者：Kurumaji T; Ishiwata S; Tokura Y

来源：PHYSICAL REVIEW B, 2017, 95(4): 045142.

DOI：10.1103/PhysRevB.95.045142

We investigate a large variation in a diagonal component of the linear magnetoelectric (ME) susceptibility in the polar ferrimagnet Mn2Mo3O8 while changing the magnetic-ion site from orbital-quenched Mn2+ to Fe2+ with strong uniaxial anisotropy. In Mn2Mo3O8, the linear ME susceptibility is dominated by the nonrelativistic exchange strictionmechanism, showing a positive value at low temperature and a critical behavior toward negative divergence around the transition temperature. This negative peak value becomes four times larger when 50% of Mn2+ ions are replaced with the Fe2+ ion, highlighting the beneficial perspective of the compositionally tunable ME effect. As the doped Fe increases in fraction, gradual negative shift of the ME coefficient is observed around the lowest temperature, which manifests the relativistic single-site origin of the ME susceptibility. Further doping with x greater than or similar to 75% in (Mn1-xFex)(2)Mo3O8, the ME coefficient becomes negative in the entire temperature region. Such a composition dependence can be explained in terms of the chemical preference for the two types of magnetic sites of Mn/Fe ions. The present paper demonstrates the large tunability of ME effect by substituting the magnetic ion with the primary structural/magnetic characters kept intact.

• 出版日期2017-1-26
• 单位RIKEN